Failed UPS - How Can I Verify Good Power After a Lightning Strike. 2

[racookpe1978]

Household problem, not a job-site problem.

We have two UPS power supplies (each with internal battery backups of course) for the computers and routers/WiFi's. Upon return home this evening after numerous thunder storms have passed through, the nbr 1 UPS has a "green light" on indicating the AC into the unit is OK, and a apparently good "on" LED for power output. But, the electronics plugged in do not power up. The output 120 VAC from the UPS is 0.0

On examination, both batteries within the failed UPS have failed (cases swollen, bulged) but have no visible electrolyte leakage or residue on the contacts.


1. Is complete battery failure likely or unlikely to have damaged the charging control and inverter electronics?

2. If I replace both batteries in an effort to save the UPS, how can I test the sine wave output to determine if it is satisfactory for use on the PC's again?

I have no exotic electronics testing eqpt (O-scope or the like) but I do have a digital voltmeter.

 

[itsmoked]

The batteries in typical small UPSs last between 2 and 5 years. A lot of this is based on the battery quality and the other half is on the UPS's charger quality. If these batteries lasted more than two years you can probably assume the UPS is OK and its charger is too.

Change out the batteries.

To test it plug something in. Preferably something about the UPS's maximum output rating. A couple of drop lights.

Heck it's a home computer! Use it. Just don't have it running any apps you care about. Unplug the UPS and see if the computer goes down or stays up. If you want to test further play some video game until the computer is dropped by the UPS. This will tell you about the time you can expect to keep running.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[mikekilroy]

As Keith said, prob worth replacing the batts - in BOTH units....

But first, since one seemed to have died in 1 day by possible thunderstorms, make sure it is save-able before you spend another $ 25.00 on batteries for it.

I had same symptoms on one with worn out batts recently: thunderstorm went thru, output 0v next day. batts obviously bad for a some time. Uprocessor locked up in it from storm. disconnected batts, pulled fuse, let sit a few minutes, re hooked up and it again worked fine - although as Keith said, pulling 120v plug it just dies since the old batts were NFG. Anyway, output DID turn back on so I know it will benefit again from new batts.

I think too unless you have a $ 500.00 UPS the output is NOT sinewave; just square like all cheap UPSs.

http://www.KilroyWasHere<dot>com

 

[itsmoked]

$25 ?!

Dang. My UPS takes six $46 batteries.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[DanEE]

Dang.. Dang..

Good UPS systems and batteries are expensive!

Used the Deka 24HR3000s in smaller commercial sites,

http://www.dekabatteries.com/assets/base/2008.pdf

They now retail list for around $200.00 a pop... I was able through a friend still in the business get 6 of them that had sit in the distribution center too long to be sold as new... for $50.00 each...

 

[VEBill]

In reference to household use, I think that UPSs are often more trouble than they're worth.

They're like having an unreliable guard dog that is high-maintenance, sleeps through a fraction of the burglaries, makes a huge mess once in a while, and every once in a long while eats one of the children.

If feasible, a better option is to just use a laptop.

 

[MikeHalloran]

Do the UPSes also have surge arrestors?

ISTR that MOVs often fail shorted after doing their job, as during a lightning strike. ... at which point the output would be trying to feed/heat what's left of the MOVs. ... which would give 0.0 volts out and overheated batteries if inverter output overcurrent protection is inadequate/ not present.

I.e., replacing the batteries may not be enough.






Mike Halloran
Pembroke Pines, FL, USA

 

[itsmoked]

VE1BLL; You make a pretty good comparison there. LOL

The biggest reason they don't do well at home is the lack of regular testing which is often carried out (regularly) in commercial settings. If people would just press the test button every month it would probably drop the 'failure events' to a sub 1% issue.

I do 99% of my work on a venerable Inspiron I love. Heck I've even bought four more of them on epay. And it's built-in UPSness works great. If the power goes out I have 3 or 4 hours left.

My 1200VA UPS will keep my router, phone and network modem running for about 2 weeks.

I also crawl under the desk and snake off a few extension cords to keep a drop light and occasionally the boob-tube going on short (predicted) outages.


Keith Cress
kcress -

http://www.flaminsystems.com

 

[mikekilroy]

$25 ?! Dang. My UPS takes six $46 batteries.

Well mine are little brothers to your 1200va! 2pc 12v 7ah:

example price:

http://www.batterysharks.com/12-Vol...ah_b12-7.htm?gclid=CK_l8t6q_r4CFfSjMgodgkkArA

So I lied; actually only $23.20

I agree they are (possibly) cheap additional good protection. I have around 10 running at offices and home. I regularly replace the batts in ours - go so far as magic marking date & part number on masking tape on bottom of each for ease of identifying when they get a few years old. Got 600va one on home entertainment/TV - nice when the power goes off!

http://www.KilroyWasHere<dot>com

 

[racookpe1978]

We do have a whole-house surge protector.

Replaced the internal batteries - They were 32.00 each.

Tested the output with a 120 vac light, UPS lasted 1-1/2 hours before alarming on low voltage, then it recharged properly when plugged back into the source voltage. Apparently, the UPS electronics and controls are OK.

My thanks to all for your comments above.

 

[mikekilroy]

Thank you very much for follow up report!

http://www.KilroyWasHere<dot>com

 

[JWR01]

Not to split hairs, but unplugging the UPS to test the battery isn't the best idea and could cause an issue. In the future just open the circuit breaker that feeds the outlet.

 

[mikekilroy]

JWR01, why do you say that?

http://www.KilroyWasHere<dot>com

 

[ScottyUK]

They rely the supply cable to provide a safety earth. Without it the case potential is not really defined other than by leakage paths.

 

[DanEE]

For that very reason, the standby power branch circuit (as defined by US NEC 2002 Article 702) and supplied by a commercial UPS at my residence has a separate green wire ground connection permanently tying the standby branch green wire ground to the mains ground..

Whether the UPS supply cord, or the UPS load plug is disconnected (Cord and Plug UPS installation as defined by US NEC 2002 Article 700.12e) ground is always maintained on the standby power branch circuit.

In our commercial UPS installations, we always ran an additional green wire ground from the UPS case earth point a mains grounding point.